[LinuxCNC/linuxcnc PR#148] “duplicate O-word label” in remap 2.6

This bug was first reported on emc-developers:

> [This branch] fixes a bug where
> setup.sequencenumber is set incorrectly after a remap return. In
> very rare circumstances, this can cause a “Duplicate O-word” error, as
> the parent of the HEAD commit demonstrates.